Concanavalin A, a protein extracted from jack bean, can form a precipitate with polysaccharides and glycoproteins that contain terminal α-D-glucose, α-D-mannose, or β-D-fructose residues. Based on this fact, recently we could demonstrate that nephritogenic glycoprotein in GBM and other related tissues has terminal α-D-glucose. The purpose of this paper is to demonstrate the in vitro and in vivo interaction between nephritogenic glycoprotein in kidney tissues and Concanavalin A using FITC labeled Concanavalin A. This fluorescent technique revealed that Con, canavalin A reacts specifically with GBM, TBM, blood vessel walls and cytoplasms of proximal tubules in vitro and GBM as well as TBM in vivo. These findings are strikingly similar to the in vitro, and in vivo reaction of FITC labeled anti-GBM antibody except for the positive reaction of proximal tubules. Localization of Concanavalin A in pathologic kidney and experimental demonstration of glomerular injury of Concanavalin A itself are now in progress. Our results indicate that Concanavalin A reacts specificaly with nephritogenic glycoprotein in kidney tissues.

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Anatomical correlation between the tubules and the blood vessels at the level of the outer medulla, inner medulla and papilla of the rabbit kidney were studied. The purpose of this paper is to elucidate morphologically mechanism of urine concentration in the renal medulla. Four adult rabbits were employed and their kidneys were studied with a light-microscopy and an electron-microscopy. The following results were obtained.1) Tubulo-vascular relationship. In cross section the outer medulla is consisted with many structural units. Central axis is composed of vascular bundles which are surrounded by tubules. These morphological structure are a principle unit. In the outer medulla the unit is deviled into the below-mentioned two concentric zones.(1) The central zone contains arterial and venous vasa recta. The descending tnin limbs of Henle's loop of a long nephron are located outside the venous vasa recta of the vascular bundles.(2) The pripheral zone contains the descending thin limbs of Henle's loop of short nepnron and the ascending thick limp of Henle's loop of either long or short nephrons with abundunt capillary plexus. The collecting ducts are located in the most periphery of the unit. In the inner medulla, the structure of the unit becomes somewhat irregular. The ascending thin limbs of Henle's loop are close to the collecting ducts, and the descending thin limbs of Henle's loop are nearby the venous vasa recta. The capillary plexus appears sparse, and interstitial space is wider witn more cell numbers as closing to the papilla. In the papilla these morphological relationship between the tubules and blood vessels is obscure.2) Following each pairs may play a role in the countercurrent processes ay an appropriate combinations of the pairs.(1) Arterial vasa recta and venous vasa recta.(2) Venous vasa recta and the descending thin limb of Henle's loop of a long nephron.(3) The ascending thick limb of a short nephron and the descending thin limb of the short nephron.(4) The ascending thick limb of either short or long nephrons and the collecting duct. There are indirect connection between the short nephron and the vascular bundle in central zone through capillary plexus.3) Electron-microscopical findings.(1) The epithelial cells of the descending thick limb of Henle's loop show prominant basal infoldings and abundunt large mitochondria tnat suggest the existence of active transport ability . The thin limbs of Henle's loop, especially of the ascending limbs have poor cell organellae which suggest no function of active transport.(2) The medullary blood circulation might be controled by the arterial vasa recta in the outer medulla which have the medial muscle cells. The structure of the venous vasa recta are very similar to capillaries which is of advantageous for passive diffusion of solution.

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